He named that place Massah [Testing] and Meribah [Complaining] because the Israelites complained and because they tested the Lord, asking, “Is the Lord with us or not?”
Moses said to Aaron, “Take your incense burner, put burning coals from the altar and incense in it, and go quickly into the community to make peace with the Lord for the people. The Lord is showing his anger; a plague has started.”
About the tribe of Levi he said, “Your Thummim and Urim belong to your faithful people. You tested your people at Massah. You quarreled with them at the oasis of Meribah.